(19)
(11) EP 0 538 966 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
09.03.1994 Bulletin 1994/10

(43) Date of publication A2:
28.04.1993 Bulletin 1993/17

(21) Application number: 92250242.2

(22) Date of filing: 02.09.1992
(51) International Patent Classification (IPC)5H04L 25/06, G05F 5/00, H03K 19/003, H03K 19/01, G11C 7/00
(84) Designated Contracting States:
CH DE ES FR GB IE IT LI NL

(30) Priority: 27.09.1991 US 766849

(71) Applicant: CYRIX CORPORATION
Richardson, Texas 75080 (US)

(72) Inventors:
  • Eitrheim, John K.
    Garland, Texas 75044 (US)
  • Bluhm, Mark
    Carollton, TX 75007 (US)

(74) Representative: UEXKÜLL & STOLBERG 
Patentanwälte Beselerstrasse 4
22607 Hamburg
22607 Hamburg (DE)


(56) References cited: : 
   
       


    (54) Line precharging circuits and methods


    (57) A bus precharge circuit is provided that precharges a bus line or node as an inverse function of the precharge level already attained on the bus line, such that the precharge level on the bus line is gradually approached. The precharge circuit charges the bus line to a midpoint between high and low logic states. The preexisting state of the bus line is stored and is used to select one of two voltage supplies to which the bus line may be partially pulled up or down. The switchpoint of a precharge circuit sensing gate is set to be equivalent to the switchpoint of the receiving gate of receiver on the bus line.







    Search report